tests/hash: extract test out of xf86drmHash.c

This way with follow up commits we can fix it and wire it up to
make check

v2:
 - Use xf86drmHash.h for common structs.(Jan)
 - Add test to .gitignore.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Jan Vesely <jan.vesely@rutgers.edu>

2 files changed, 200 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 75fc2413..d4674f75 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -29,7 +29,8 @@ LDADD = $(top_builddir)/libdrm.la
 
 check_PROGRAMS = \
 	dristat \
-	drmstat
+	drmstat \
+	hash
 
 if HAVE_NOUVEAU
 SUBDIRS += nouveau
diff --git a/tests/hash.c b/tests/hash.c
new file mode 100644
index 00000000..517a667c
--- /dev/null
+++ b/tests/hash.c
@@ -0,0 +1,198 @@
+/* xf86drmHash.c -- Small hash table support for integer -> integer mapping
+ * Created: Sun Apr 18 09:35:45 1999 by faith@precisioninsight.com
+ *
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@valinux.com>
+ *
+ * DESCRIPTION
+ *
+ * This file contains a straightforward implementation of a fixed-sized
+ * hash table using self-organizing linked lists [Knuth73, pp. 398-399] for
+ * collision resolution.  There are two potentially interesting things
+ * about this implementation:
+ *
+ * 1) The table is power-of-two sized.  Prime sized tables are more
+ * traditional, but do not have a significant advantage over power-of-two
+ * sized table, especially when double hashing is not used for collision
+ * resolution.
+ *
+ * 2) The hash computation uses a table of random integers [Hanson97,
+ * pp. 39-41].
+ *
+ * FUTURE ENHANCEMENTS
+ *
+ * With a table size of 512, the current implementation is sufficient for a
+ * few hundred keys.  Since this is well above the expected size of the
+ * tables for which this implementation was designed, the implementation of
+ * dynamic hash tables was postponed until the need arises.  A common (and
+ * naive) approach to dynamic hash table implementation simply creates a
+ * new hash table when necessary, rehashes all the data into the new table,
+ * and destroys the old table.  The approach in [Larson88] is superior in
+ * two ways: 1) only a portion of the table is expanded when needed,
+ * distributing the expansion cost over several insertions, and 2) portions
+ * of the table can be locked, enabling a scalable thread-safe
+ * implementation.
+ *
+ * REFERENCES
+ *
+ * [Hanson97] David R. Hanson.  C Interfaces and Implementations:
+ * Techniques for Creating Reusable Software.  Reading, Massachusetts:
+ * Addison-Wesley, 1997.
+ *
+ * [Knuth73] Donald E. Knuth. The Art of Computer Programming.  Volume 3:
+ * Sorting and Searching.  Reading, Massachusetts: Addison-Wesley, 1973.
+ *
+ * [Larson88] Per-Ake Larson. "Dynamic Hash Tables".  CACM 31(4), April
+ * 1988, pp. 446-457.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "xf86drm.h"
+#include "xf86drmHash.h"
+
+#define DIST_LIMIT 10
+static int dist[DIST_LIMIT];
+
+static void clear_dist(void) {
+    int i;
+
+    for (i = 0; i < DIST_LIMIT; i++) dist[i] = 0;
+}
+
+static int count_entries(HashBucketPtr bucket)
+{
+    int count = 0;
+
+    for (; bucket; bucket = bucket->next) ++count;
+    return count;
+}
+
+static void update_dist(int count)
+{
+    if (count >= DIST_LIMIT) ++dist[DIST_LIMIT-1];
+    else                     ++dist[count];
+}
+
+static void compute_dist(HashTablePtr table)
+{
+    int           i;
+    HashBucketPtr bucket;
+
+    printf("Entries = %ld, hits = %ld, partials = %ld, misses = %ld\n",
+	   table->entries, table->hits, table->partials, table->misses);
+    clear_dist();
+    for (i = 0; i < HASH_SIZE; i++) {
+	bucket = table->buckets[i];
+	update_dist(count_entries(bucket));
+    }
+    for (i = 0; i < DIST_LIMIT; i++) {
+	if (i != DIST_LIMIT-1) printf("%5d %10d\n", i, dist[i]);
+	else                   printf("other %10d\n", dist[i]);
+    }
+}
+
+static void check_table(HashTablePtr table,
+			unsigned long key, unsigned long value)
+{
+    unsigned long retval  = 0;
+    int           retcode = drmHashLookup(table, key, &retval);
+
+    switch (retcode) {
+    case -1:
+	printf("Bad magic = 0x%08lx:"
+	       " key = %lu, expected = %lu, returned = %lu\n",
+	       table->magic, key, value, retval);
+	break;
+    case 1:
+	printf("Not found: key = %lu, expected = %lu returned = %lu\n",
+	       key, value, retval);
+	break;
+    case 0:
+	if (value != retval)
+	    printf("Bad value: key = %lu, expected = %lu, returned = %lu\n",
+		   key, value, retval);
+	break;
+    default:
+	printf("Bad retcode = %d: key = %lu, expected = %lu, returned = %lu\n",
+	       retcode, key, value, retval);
+	break;
+    }
+}
+
+int main(void)
+{
+    HashTablePtr table;
+    int          i;
+
+    printf("\n***** 256 consecutive integers ****\n");
+    table = drmHashCreate();
+    for (i = 0; i < 256; i++) drmHashInsert(table, i, i);
+    for (i = 0; i < 256; i++) check_table(table, i, i);
+    for (i = 256; i >= 0; i--) check_table(table, i, i);
+    compute_dist(table);
+    drmHashDestroy(table);
+
+    printf("\n***** 1024 consecutive integers ****\n");
+    table = drmHashCreate();
+    for (i = 0; i < 1024; i++) drmHashInsert(table, i, i);
+    for (i = 0; i < 1024; i++) check_table(table, i, i);
+    for (i = 1024; i >= 0; i--) check_table(table, i, i);
+    compute_dist(table);
+    drmHashDestroy(table);
+
+    printf("\n***** 1024 consecutive page addresses (4k pages) ****\n");
+    table = drmHashCreate();
+    for (i = 0; i < 1024; i++) drmHashInsert(table, i*4096, i);
+    for (i = 0; i < 1024; i++) check_table(table, i*4096, i);
+    for (i = 1024; i >= 0; i--) check_table(table, i*4096, i);
+    compute_dist(table);
+    drmHashDestroy(table);
+
+    printf("\n***** 1024 random integers ****\n");
+    table = drmHashCreate();
+    srandom(0xbeefbeef);
+    for (i = 0; i < 1024; i++) drmHashInsert(table, random(), i);
+    srandom(0xbeefbeef);
+    for (i = 0; i < 1024; i++) check_table(table, random(), i);
+    srandom(0xbeefbeef);
+    for (i = 0; i < 1024; i++) check_table(table, random(), i);
+    compute_dist(table);
+    drmHashDestroy(table);
+
+    printf("\n***** 5000 random integers ****\n");
+    table = drmHashCreate();
+    srandom(0xbeefbeef);
+    for (i = 0; i < 5000; i++) drmHashInsert(table, random(), i);
+    srandom(0xbeefbeef);
+    for (i = 0; i < 5000; i++) check_table(table, random(), i);
+    srandom(0xbeefbeef);
+    for (i = 0; i < 5000; i++) check_table(table, random(), i);
+    compute_dist(table);
+    drmHashDestroy(table);
+
+    return 0;
+}